Generally an inkjet head is a device which ejects ink drops onto desirable positions on a recording medium to form an image. The inkjet head is categorized into two categories dependent upon its inkjet mechanism. The first category relates to a thermal inkjet head which ejects ink drops under an expansive force of gas bubbles thermally produced in the ink. The other category relates to a piezoelectric inkjet head which ejects ink drops under a pressure applied to the ink due to piezoelectric deformation.
Recently, the inkjet head has been applied in the field of imaging, and other fields. For example, a color filter sheet of a Liquid Crystal Display (LCD) has been fabricated using the inkjet head. The color filter sheet has been fabricated through dyeing, pigment dispersing, printing, and electro-deposition. Printing method for fabricating an Organic Light-Emitting Diode (OLED) product has got attention by more and more manufacturers, and has become a key development focus of the respective manufacturers. However there are a high precision required for the position where the device prints, and a high precision required for the volume of ink, and if the precision of the position where the device prints is low, then the ink drops will fail to enter pixels; and if the precision of the volume of the ink is low, then there will be uneven display. In view of this, a precise measurement of the volume of an ink drop is of great importance to a superior product to be manufactured.
At present, there is a big measurement error, and cumbersome calculating process of the volume of an ink drop, in the method for measuring the volume of an ink drop in the existing apparatus.